Genetic sharing and heritability of paediatric age of onset autoimmune diseases.
Li YR., Zhao SD., Li J., Bradfield JP., Mohebnasab M., Steel L., Kobie J., Abrams DJ., Mentch FD., Glessner JT., Guo Y., Wei Z., Connolly JJ., Cardinale CJ., Bakay M., Li D., Maggadottir SM., Thomas KA., Qui H., Chiavacci RM., Kim CE., Wang F., Snyder J., Flatø B., Førre Ø., Denson LA., Thompson SD., Becker ML., Guthery SL., Latiano A., Perez E., Resnick E., Strisciuglio C., Staiano A., Miele E., Silverberg MS., Lie BA., Punaro M., Russell RK., Wilson DC., Dubinsky MC., Monos DS., Annese V., Munro JE., Wise C., Chapel H., Cunningham-Rundles C., Orange JS., Behrens EM., Sullivan KE., Kugathasan S., Griffiths AM., Satsangi J., Grant SFA., Sleiman PMA., Finkel TH., Polychronakos C., Baldassano RN., Luning Prak ET., Ellis JA., Li H., Keating BJ., Hakonarson H.
Autoimmune diseases (AIDs) are polygenic diseases affecting 7-10% of the population in the Western Hemisphere with few effective therapies. Here, we quantify the heritability of paediatric AIDs (pAIDs), including JIA, SLE, CEL, T1D, UC, CD, PS, SPA and CVID, attributable to common genomic variations (SNP-h(2)). SNP-h(2) estimates are most significant for T1D (0.863±s.e. 0.07) and JIA (0.727±s.e. 0.037), more modest for UC (0.386±s.e. 0.04) and CD (0.454±0.025), largely consistent with population estimates and are generally greater than that previously reported by adult GWAS. On pairwise analysis, we observed that the diseases UC-CD (0.69±s.e. 0.07) and JIA-CVID (0.343±s.e. 0.13) are the most strongly correlated. Variations across the MHC strongly contribute to SNP-h(2) in T1D and JIA, but does not significantly contribute to the pairwise rG. Together, our results partition contributions of shared versus disease-specific genomic variations to pAID heritability, identifying pAIDs with unexpected risk sharing, while recapitulating known associations between autoimmune diseases previously reported in adult cohorts.